/* 7zCrcOpt.c -- CRC32 calculation : optimized version
   2009-11-23 : Igor Pavlov : Public domain */

#include "Types.h"
#include "CpuArch.h"

#ifdef MY_CPU_LE

    #define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))

UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void* data, size_t size, const UInt32* table)
{
    const Byte* p = (const Byte*)data;
    for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
        v = CRC_UPDATE_BYTE_2(v, *p);
    for (; size >= 4; size -= 4, p += 4)
    {
        v ^= *(const UInt32*)p;
        v =
            table[0x300 + (v & 0xFF)] ^
            table[0x200 + ((v >> 8) & 0xFF)] ^
            table[0x100 + ((v >> 16) & 0xFF)] ^
            table[0x000 + ((v >> 24))];
    }
    for (; size > 0; size--, p++)
        v = CRC_UPDATE_BYTE_2(v, *p);
    return v;
}

UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void* data, size_t size, const UInt32* table)
{
    return CrcUpdateT4(v, data, size, table);
}

#endif